arm64: dts: rockchip: Support poweroff on Orange Pi 5

The RK806 on the Orange Pi 5 can be used to power on/off the whole board.
Mark it as the system power controller.
Signed-off-by: Jimmy Hon <honyuenkwun@gmail.com>
Link: https://lore.kernel.org/r/20231227203211.1047-1-honyuenkwun@gmail.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>

arch/arm64/boot/dts/rockchip/rk3588s-orangepi-5.dts

@@ -314,6 +314,7 @@ pmic@0 {
 		pinctrl-0 = <&pmic_pins>, <&rk806_dvs1_null>,
 				<&rk806_dvs2_null>, <&rk806_dvs3_null>;
 		spi-max-frequency = <1000000>;
+		system-power-controller;
 
 		vcc1-supply = <&vcc5v0_sys>;
 		vcc2-supply = <&vcc5v0_sys>;